Paper conveying apparatus, image forming apparatus and ink-jet recording apparatus

ABSTRACT

A sheet of paper is conveyed by a convey roller to a print receiving member and pushed forward thereon while being supported by ribs and pressed downward by pressing members so as to keep a predetermined distance between the paper and a recording head while an image is printed on the paper. Since the pressing members press respective side portions of the paper, the paper can be bent downward outside the outmost ribs and prevented from rising at the side portions.

TECHNICAL FIELD

The present invention relates to a paper conveying apparatus, an imageforming apparatus and an ink-jet recording apparatus; more particularlyto a paper conveying apparatus, an image forming apparatus and anink-jet recording apparatus that have a print receiving member arrangedopposed to a print head.

BACKGROUND ART

Conventionally, an ink-jet recording apparatus used as an imagerecording apparatus (image forming apparatus) such as a printer, afacsimile, a copier or the like can form an image on a sheet of paper(not necessarily limited to paper but whatever is used to form an imagethereon) by ejecting ink droplets from a nozzle of an ink-jet headthereto. Since deviation of the positional relationship between thesheet of paper and the ink-jet head may degrade image quality, it isrequired to convey the sheet of paper with accuracy.

Since the ink-jet recording apparatus allows ink droplets to adhere on asheet of paper, the paper tends to become corrugated. Namely, within afew seconds after the ink droplets adhere on the paper, the paper swellsand then becomes corrugated, which is known as so-called cackling.Typically, when an image is printed on a sheet of paper, there aremargins formed on the right, left, top, and bottom of the paper.Therefore, tensile stress is caused between the right (left) margin anda printed area adjacent to the right (left) margin, which pulls both themargins inward, thereby causing both side portions of the paper to rise.If this happens, the paper cannot be flat in relation to the ink-jethead, and a gap between the paper and the ink-jet head varies, therebydistorting the image. Moreover, a large corrugation of the paper causesa problem in that the image printed on the paper may be defective andthe ink-jet head may be damaged or broken since the paper can contactthe ink-jet head.

In order to eliminate such disadvantages, an image forming apparatussuch as an ink-jet printer has been proposed in recent years, where aconveyor roller is disposed in both the upstream and the downstream endof a paper conveying direction so as to maintain the flatness of thepaper in relation to the ink-jet head. Such an image forming apparatuscan prevent the paper from becoming corrugated during printing (See,patent-related publications listed below).

[Patent-related document 1] Japanese Patent Application Laid-OpenPublication No. H7-125364.

[Patent-related document 2] Japanese Patent Application Laid-OpenPublication No. H7-132659.

[Patent-related document 3] Japanese Patent Application Laid-OpenPublication No. H9-24650.

[Patent-related document 4] Japanese Patent Application Laid-OpenPublication No. 2001-261188.

However, in such an ink jet recording apparatus where the conveyorrollers are provided in the upstream and the downstream end of the paperalong the conveying direction, an image is printed on the paper whilethe conveyer rollers are holding the leading and the rear ends of thepaper. Therefore, a relatively larger non-printed zone has to beallocated at the upper and lower portions of the paper (i.e., theleading margin and the rear margin), which leads to another problem inthat the printable area becomes smaller.

The present invention has been made in view of the above, and mayprovide a paper conveying apparatus, an image forming apparatus and anink-jet recording apparatus that can press side portions of paperdownward so as to allow the paper to bend downward.

DISCLOSURE OF THE INVENTION

An embodiment of the present invention provides a paper conveyingapparatus including a first paper pressing member configured to pressone side portion of a sheet of paper that may be conveyed therethrough,the side portion extending along a paper conveying direction.

Another embodiment of the present invention provides the paper conveyingapparatus, where the first paper pressing member is disposed so that adownstream portion thereof along the paper conveying direction liesoutward in a direction transverse to the paper conveying direction froman upstream portion thereof.

Another embodiment of the present invention provides the paper conveyingapparatus, where the first paper pressing member is disposed so that acenter of a downstream portion thereof along the paper conveyingdirection lies outward in a direction transverse to the paper conveyingdirection from a center of an upstream portion thereof.

Another embodiment of the present invention provides the paper conveyingapparatus, where the first paper pressing member is disposed so that acenter of a downstream portion thereof along the paper conveyingdirection lies outward in a direction transverse to the paper conveyingdirection from a corresponding one edge of the sheet of paper.

Another embodiment of the present invention provides the paper conveyingapparatus, where the first paper pressing member is disposed so that amiddle portion thereof between a downstream portion thereof and anupstream portion thereof along the paper conveying direction liesoutward from a corresponding one edge of the sheet of paper.

Another embodiment of the present invention provides the paper conveyingapparatus, where the first paper pressing member becomes narrower towarda downstream end thereof along the paper conveying direction.

Another embodiment of the present invention provides the paper conveyingapparatus further including one or more supporting members configured tosupport the sheet of paper from below.

Another embodiment of the present invention provides the paper conveyingapparatus further including a second paper pressing member configured topress the other side portion of the sheet of paper.

Another embodiment of the present invention provides the paper conveyingapparatus, where the second paper pressing member is symmetric in shapewith the first paper pressing member in relation to the paper conveyingdirection.

Another embodiment of the present invention provides the paper conveyingapparatus, further including one or more third paper pressing memberscapable of pressing the sheet of paper between the first and the secondpaper pressing members.

Another embodiment of the present invention provides the paper conveyingapparatus, where the first or the second paper pressing member pressesone side portion of the sheet of paper and one of the one or more thirdpaper pressing members presses the other side portion of the sheet ofpaper, and where the one of the one or more third paper pressing membersis disposed symmetrically with the first or the second paper pressingmember in relation to the paper conveying direction.

Another embodiment of the present invention provides the paper conveyingapparatus further including one or more paper pressing amount limitingmembers disposed below the sheet of paper and configured to besubstantially vertically movable so as to limit an amount of pressing onthe sheet of paper caused by the first paper pressing member, the secondpaper pressing member, the third paper pressing member, or a combinationthereof.

Another embodiment of the present invention provides the paper conveyingapparatus further including one or more supporting members configured tosupport the sheet of paper from below, where the one or more paperpressing amount limiting members push from below the sheet of paper thatis held from below by the supporting member and pressed from above bythe first paper pressing member, the second paper pressing member, thethird paper pressing member, or a combination thereof, so as to limitthe amount of pressing from above.

Another embodiment of the present invention provides the paper conveyingapparatus, wherein each of the one or more third paper pressing membersis disposed between every adjacent two of the supporting members, andwherein one of the one or more supporting members, the corresponding oneof the one or more paper pressing amount limiting members, and thecorresponding one of the one or more third paper pressing members aredisposed in this order in a direction transverse to the paper conveyingdirection.

Another embodiment of the present invention provides the paper conveyingapparatus, wherein each of the one or more third paper pressing membersis disposed between every adjacent two of the supporting members, andwherein one of the one or more third paper pressing members, thecorresponding one of the one or more supporting members, and thecorresponding one of the one or more paper pressing amount limitingmembers are disposed in this order in a direction transverse to thepaper conveying direction.

Another embodiment of the present invention provides the paper conveyingapparatus, where each of the one or more paper pressing amount limitingmembers is disposed below a corresponding one of the one or more thirdpaper pressing members.

Another embodiment of the present invention provides the paper conveyingapparatus, where one of the one or more paper pressing amount limitingmembers is disposed between the first paper pressing member and thethird paper pressing member adjacent to the first paper pressing member.

Another embodiment of the present invention provides the paper conveyingapparatus, where one of the one or more paper pressing amount limitingmembers is disposed between the second paper pressing member and thethird paper pressing member adjacent to the second paper pressingmember.

Another embodiment of the present invention provides the paper conveyingapparatus, where at least one of the one or more paper pressing amountlimiting members is disposed outward in a direction transverse to thepaper conveying direction from a corresponding edge of the sheet ofpaper.

Another embodiment of the present invention provides the paper conveyingapparatus, where a first set of the one or more paper pressing amountlimiting members is disposed below the corresponding third paperpressing members and where a second set of the one or more paperpressing amount limiting members is disposed between every adjacent twoof the third paper pressing members.

Another embodiment of the present invention provides the paper conveyingapparatus further including: a print receiving member disposed opposinga print head that prints on the sheet of paper; a conveying rollerconfigured to convey the sheet of paper to the print receiving member;and a pressing roller configured to press the sheet of paper on theconveying roller, where at least one of the first, the second, and thethird paper pressing members is configured to press the sheet of paperon the print receiving member.

Another embodiment of the present invention provides the paper conveyingapparatus further including one or more supporting members disposed onthe print receiving member so as to support the sheet of paper frombelow.

Another embodiment of the present invention provides an image formingapparatus comprising at least the paper conveying apparatus.

Another embodiment of the present invention provides an ink-jetrecording apparatus comprising at least the paper conveying apparatus.

According to the embodiments of the present invention, there is provideda paper conveying apparatus, an image forming apparatus and an ink-jetrecording apparatus that can press side portions of paper downward so asto allow the paper to bend downward.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of an ink-jet recordingapparatus according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view of a print receiving member andthe vicinity thereof in the ink-jet recording apparatus according to theembodiment of the present invention.

FIG. 3 is a plan view of the print receiving member of the ink-jetrecording apparatus according to the embodiment of the presentinvention.

FIG. 4 is a front view of pressing members and the vicinity thereof inthe ink-jet recording apparatus according to the embodiment of thepresent invention.

FIGS. 5( a) and 5(b) show other examples of the pressing members havingdifferent shapes.

FIGS. 6( a) through 6(f) show still other examples of the pressingmembers having different shapes.

FIGS. 7( a) through 7(d) show still other examples of the pressingmembers having different shapes.

FIG. 8 is a plan view of the print receiving member in which thepressing members are disposed differently from the pressing members inFIG. 3.

FIGS. 9( a) through 9(c) are front views of the pressing amount limitingmembers disposed in three respective positions in relation to thepressing members.

FIG. 10 is a front view of the pressing amount limiting members disposedoutside the corresponding one of the pressing members.

FIG. 11 is a plan view of the print receiving member in which each ofthe pressing amount limiting members is disposed outside thecorresponding one of the pressing members.

FIG. 12 is a front view of the pressing amount limiting members disposedbelow the corresponding pressing members.

FIG. 13 is a plan view of the print receiving member in which thepressing amount limiting members are disposed below the correspondingpressing members.

FIG. 14 is a front view for depicting that a sheet of paper which hasthe edge thereof extending beyond the pressing member is dealt with bythe pressing members and the pressing amount limiting members.

FIG. 15 is another front view of the pressing amount limiting membersdisposed below the corresponding pressing members except for the outmost(leftmost) pressing member.

FIG. 16 is another plan view of the print receiving member in which thepressing amount limiting members disposed below the correspondingpressing members except for the outmost (leftmost) pressing member.

FIG. 17 is a front view of the pressing amount limiting members aredisposed inside the corresponding one of the pressing members.

FIG. 18 is a plan view of the print receiving member in which thepressing amount limiting members are disposed inside the correspondingone of the pressing members.

FIG. 19 is another front view of the pressing amount limiting membersdisposed inside the corresponding one of the pressing members except forthe outmost (leftmost) pressing member.

FIG. 20 is another plan view of the print receiving member in which thepressing amount limiting members are disposed inside the correspondingone of the pressing members except for the outmost (leftmost) pressingmember.

FIGS. 21( a) and 21(b) are schematic side views for explaining how thepressing members and the pressing amount limiting member may functiondifferently depending on the size of the paper.

FIGS. 22( a) and 22(b) are schematic side views illustrating that twopressing amount limiting members are arranged between the pressingmembers.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the accompanying drawings, a paper conveying apparatus, animage forming apparatus and an ink jet recording apparatus according toembodiments of the present invention are described hereinafter. Sincethe following embodiments are illustrated only as preferred embodimentsof the present invention, technologically preferable limitations areadded thereto. However, the present invention is not limited to theembodiments disclosed herein unless a particular limitation is recitedin the following description.

[Ink-Jet Recording Apparatus]

FIG. 1 is a schematic cross-sectional view of an ink-jet recordingapparatus according to one embodiment of the present invention. Therecording apparatus houses a printing mechanism portion 2 configured tohave a carriage 13 movable along the main scanning direction(perpendicular to the paper surface of FIG. 1) in a recording apparatusbody 1, a recording head 14 composed of an ink-jet head mounted on thecarriage 13, and an ink cartridge 15 configured to supply ink to therecording head 14, or the like. The details thereof are describedhereinafter.

In the lower portion of the recording apparatus body 1, a paper feedcassette 4 into which plural sheets of paper 3 can be placed from thefront portion thereof is removably loaded. By the way, the paper 3 canbe fed from a paper feed tray (not shown) instead of the paper feedcassette 4.

The paper 3 that has once been placed in the paper feed cassette 4 isconveyed through a path defined by a paper feed roller 21 and a frictionpad 22 which can cooperatively separate one sheet of paper 3 from othersheets of paper 3 in the paper feed cassette 4, a conveyance roller 24which reverses the direction of the paper 3 conveyed from the paper feedcassette 4 to feed the paper 3 forward, and a conveyance roller 26 thatdefines an ejection angle of the paper 3 that has been ejected from theconveyance roller 24 and an associated conveyance roller 25 that isdisposed pressed toward the circumferential surface of the conveyanceroller 24. Having traveled through this path, the paper 3 finallyreaches the printing mechanism portion 2.

The printing mechanism portion 2 is composed of the carriage 13, therecording head 14, and the ink tank 15, or the like, and functions toprint the paper 3.

The carriage 13 is held by a main guide rod 11 and a sub guide rod 12supported by right and left side plates (not shown) so as to slidablymove in the main scanning direction (perpendicular to the paper surfaceof FIG. 1).

The recording head 14 is mounted on the undersurface of the carriage 13so as to eject ink droplets downward. The recording head 14 is composedof the ink-jet head having nozzles for ejecting ink droplets of yellow(Y), cyan (C), magenta (M), and black (Bk). By the way, the recordinghead 14 may be composed of plural heads that are disposed side-by-sidein the main scanning direction and eject ink droplets of respectivecolors. In addition, the recording head 14 may be composed of one headhaving nozzles capable of ejecting ink droplets of corresponding colors.

Below the recording head 14, a print receiving member 27 is arranged asa guide configured to guide the paper 3.

The ink tank (ink cartridge) 15 is configured to supply ink of eachcolor to the corresponding recording head 14. The ink tank 15 isreplaceably mounted on the carriage 13.

On the paper 3 conveyed to the printing mechanism portion 2 is printedan image by the recording head 14, and then the paper 3 with the imagethereon is further conveyed to a paper ejection tray 6 by aconfiguration described below.

Downstream from the print receiving member 27 along the paper conveyingdirection (or along the rightward direction in FIG. 1), a conveyorroller 31 and a spur 32 are arranged for conveying forward (orrightward) the paper 3. Additionally, downstream from the conveyorroller 31 and the spur 32, guide members 35, 36 are arranged so as todefine a paper ejection path. Furthermore, downstream therefrom, a paperejection roller 33 and a spur 34 are arranged for conveying the paper 3toward the paper ejection tray 6.

[Print Receiving Member 27]

Referring to FIG. 2, the print receiving member 27 is detailedhereinafter. FIG. 2 is a schematic perspective view of the printreceiving member 27 and the vicinity thereof in the ink-jet recordingapparatus 1 according to this embodiment of the present invention. FIG.3 is a plan view of the print receiving member 27 of the ink-jetrecording apparatus 1 according to this embodiment of the presentinvention. FIG. 4 is a front view of pressing members 101, 102 and thevicinity thereof in the ink-jet recording apparatus 1 according to thisembodiment of the present invention.

Referring to FIG. 2, the print receiving member 27 is provided withplural ribs (supporting members) 29. The ribs 29 are arranged so as todefine a predetermined gap between the paper 3 and the recording head14. As shown in FIG. 2, the outermost ribs of the plural ribs 29 arepositioned slightly inside the side edge of the paper 3. Preferably, thedistance between each of the outermost ribs 29 and the correspondingside edge of the paper 3 is less than or equal to 10 mm. Morepreferably, the distance therebetween is less than or equal to 5 mm. Anattachment portion 28 is provided with the plural pressing members 101,102, which are discussed in detail below.

The paper 3 conveyed to the print receiving member 27 is presseddownward by the pressing members 101, 102 and conveyed on and along theribs 29 disposed on the print receiving member 27. In this manner, apredetermined gap between the paper 3 and the print head 14 is defined.Onto the paper 3 are adhered ink droplets ejected from the print head 14and thus a predetermined image is formed thereon.

Among the plural pressing members 101, 102, the outermost pressingmembers 101 (first and second paper pressing members) on both sides canpress respective side portions of the paper 3 downward. This allows theside portions of the paper 3 to be bent downwardly in areas outside theoutermost ribs 29 (see FIG. 4), thereby preventing the side portionsfrom rising. By the way, a “side portion” here should be understood asbeing an area near the paper edge extending along the paper conveyingdirection.

In addition, due to such bending of the paper 3 in both side portions,the paper 3 can be maintained flat even between two adjacent ribs,therefore maintaining constant the gap between the paper 3 and therecording head 14. Moreover, the paper 3 is prevented from contactingthe recording head 14 even if the paper swells after absorbing inkdroplets, thereby preventing the image thereon from being degraded andthe recording head 14 from being damaged.

As stated above, due to a simple configuration of the plural ribs 29disposed on the print receiving member 27 so as to oppose the recordinghead 14, the pressing members 101 disposed so as to press the sideportions of the paper 3 downward, and the pressing members 102 arrangedbetween every two adjacent ribs in this non-limiting embodiment, thepaper 3 is prevented from contacting the recording head 14.

[Pressing Member]

Next, the pressing members 101, 102 attached to the attachment portion28 are described in detail. Each of pressing members 101, 102 accordingto this embodiment is attached to the attachment portion 28 at theupstream side (or “A” side in FIG. 3) of the print receiving member 27and extends toward the downstream side (or “B” side in FIG. 3), as shownin FIG. 3. Particularly, the pressing members 101 are arranged outsidethe outmost ribs 29, thereby preventing the side portions of the paper 3from rising, as described above.

In addition, since the pressing members 101 are arranged in a symmetricrelationship with each other as shown in FIG. 3, the paper 3 isprevented from rising to a substantially equal degree in both sideportions.

By the way, when a paper having a smaller width than the paper 3illustrated in FIG. 3 is conveyed, other pressing members (i.e.,pressing members 102) positioned inside the pressing members 101 canpress the side portions of the paper downward. For example, the pressingmembers 102 (a third paper pressing member) can press downward on theside portions of the paper illustrated by a dotted line in FIG. 3.Therefore, the narrower paper can also be prevented from rising upwardin both side portions.

By the way, the pressing members 101, 102 shown in FIG. 3 are arrangedsymmetrically in relation to a central point of the print receivingmember 27, since the paper rests on the print receiving member 27 sothat the center of the paper coincides with the central point of thereceiving member 27. In contrast, the pressing members 101, 102 may bearranged asymmetrically as shown in FIG. 8, which is suitable when thepaper is left-aligned. Specifically, when the paper 3 shown by a dottedline in FIG. 8, which is narrower than the paper 3 shown by a solidline, is conveyed therein, the right edge of the narrower paper can bepressed downward by either one of the pressing members 102.

FIGS. 5( a) and 5(b) show additional examples of the pressing member 101according to this embodiment of the present invention. As shown in FIG.5( a), the pressing member 101 has a distal point B which is a downwardpoint in the paper conveying direction. The distal point B lies outward(leftward in FIG. 5( a)) and downstream from a center point A on theupstream side of the pressing member 101.

Additionally, the distal point B is disposed outside the edge (dottedline) of the paper. Moreover, not only the distal point B but at least aportion on the downstream side thereof is also disposed outside the edgeof the paper.

As shown in FIG. 5( b), the pressing member 101 as the other example hasa distal point C that lies outward (leftward in FIG. 5( b)) anddownstream from a corner point D on the upstream side thereof.

FIGS. 6( a) through 6(f) show still other examples of the pressingmember 101. All the pressing members 101 illustrated therein aredisposed so as to press the left side portion of the paper downward.

The pressing members 101 having such shapes as illustrated in FIGS. 5(a), 5(b), and 6(a) through 6(f) can apply a greater pressing force tothe side portion of the paper as the paper proceeds downward, therebyassuredly preventing the side portion of the paper from rising upward.

Moreover, even when the side portion of the paper shifts slightly in thedirection transverse to the paper conveying direction, the edge of thepaper can touch the pressing member 101 and be pressed downward.Therefore, the side portion of the paper 3 can be bent downward by aweaker pressing force.

Furthermore, since the side portion of the paper, which is easily bentor warped upward, can be pressed downward, the paper is prevented frombeing contaminated or jammed.

In addition, since the pressing member 101 is narrower in the downstreamportion thereof than in the upstream portion thereof, the pressingmember 101 can press the side portion of the paper downward with aweaker force, thereby allowing the paper to be kept flat as a whole andthus providing a better quality image. If the pressing force becomes toostrong, the paper cannot be maintained flat, since the stronger forcemay cause the paper to drop between the ribs, which in turn makes itdifficult to maintain the paper flat in relation to the recording head14 (FIG. 1).

Additionally, the outmost ribs 29, which are disposed near the sideportions of the paper, can help keep the paper flat, thereby providing abetter quality image. Moreover, since the pressing members 101 aredisposed outside the outmost ribs 29, the pressing members 101 canprevent the side portion of the paper from rising upward.

FIGS. 7( a) through 7(d) show various other examples of the pressingmembers 101. Specifically, FIGS. 7( a) through 7(c) show pressingmembers having identical widths along the paper conveying direction,which are different from the pressing members 101 illustrated in FIGS.5( a), 5(b), and FIGS. 6( a) through 6(f).

More specifically, as shown in FIG. 7( a), the pressing member 101 isdisposed so that a center point B at the rear (or downstream) endthereof lies outside the paper edge whereas a center point A at thefront (or upstream) end thereof lies substantially above the paper edgeshown by a dotted line.

In FIG. 7( b), the pressing member 101 is disposed so that the centerpoint B at the rear (or downstream) end thereof lies outside the paperedge whereas the center point A at the front (or upstream) end thereoflies inside the paper edge.

In FIG. 7( c), the pressing member 101 is disposed so that the centerpoints A and B lie inside the paper edge. Although not only the point Abut also the point B lies inside the paper edge in this case, at least aportion of the pressing member 101 can extend outward from the paperedge. Therefore, this pressing member 101 can also press the paper edgedownward.

In FIG. 7( d), the pressing member 101 has a rectangular shape and isdisposed so that both the center point B at the rear (or downstream) endthereof and the center point A at the front (or upstream) end thereoflie substantially above the paper edge.

Even these pressing members 101 illustrated in FIGS. 7( a) through 7(d)can prevent the paper from rising upward evenly in both side portions ofthe paper when the pressing members 101 are disposed on both sides ofthe print receiving member 27. In addition, such pressing members 101can prevent the side portions of the narrower paper from rising upward.

[Pressing Amount Limiting Member]

Next, a pressing amount limiting member according to one embodiment ofthe present invention is described. In the foregoing embodiments, thepressing members 101 press the paper outside the outmost ribs 29downward. In addition, since plural pressing members 102 are disposed onthe inner side of the pressing members 101, even when narrower paper isused, the paper can be bent downward on both side portions (see FIG. 3).

However, the plural pressing members 102 may press the paper downward toa greater extent between all adjacent ribs 29, which may cause thepaper, which has to be kept flat in relation to the recording head 14,to be unnecessarily bent. In order to prevent such unnecessary bending,a pressing amount limiting member 30 is provided in this embodiment.That is, an amount of pressing on the paper caused by the pressingmembers 102 can be adjusted by adjusting the elevation of the pressingamount limiting member 30.

The pressing amount limiting member 30 is disposed on the printreceiving member 27. Specifically, the pressing amount limiting member30 may be disposed in three positions in relation to the pressingmembers 101, 102 as shown in FIGS. 9( a) through 9(c), although theposition cannot be strictly limited to the three positions as long asthe pressing amount limiting member 30 can restrict the amount ofpressing the paper 3 caused by the pressing members 102.

In FIG. 9( a), the pressing amount limiting member 30 is disposedoutside (or on the left-hand side of) the pressing member 102 betweenthe ribs 29. In FIG. 9( a), the pressing amount limiting member 30 isdisposed below the pressing member 102. In other words, the pressingamount limiting member 30 is disposed so that a portion of the paperpressed downward by the pressing member 102 is held by the pressingamount limiting member 30. In FIG. 9( c), the pressing amount limitingmember 30 is disposed inside (or on the right-hand side of) the pressingmember 102 between the ribs 29. The pressing amount limiting members 30disposed as shown in FIGS. 9( a) through 9(c) are discussed in detailhereinafter.

First, the pressing amount limiting member 30 disposed outside thepressing member 102 is described with reference to FIGS. 9( a), 10, and11. FIG. 10 is an explanatory view showing that each of additionalpressing amount limiting members 30 is disposed outside thecorresponding one of the pressing members 102. FIG. 11 is a plan view ofthe print receiving member 27 in which each of the additional pressingamount limiting members 30 is disposed outside the corresponding one ofthe pressing members 102. It should be understood from FIGS. 10 and 11that a rib 29, a pressing amount limiting member 30, and a third paperpressing member 102 are disposed in this order in a direction from theside edge to the center of the paper 3. The amount of pressing the paper3 caused by the pressing members 102 can be adjusted by adjusting theelevation of the pressing amount limiting members 30 so disposed.

As shown in FIG. 10, the pressing amount limiting members 30 have alower height (vertical length) than the ribs 29. In other words, thepressing amount limiting members 30 are not required to have a heighthigher than or equal to the ribs 29 because the pressing amount limitingmembers 30 are not configured to adjust the gap between the paper 3 andthe recording head 14, whereas the ribs 29 disposed on the printreceiving member 27 are configured to define the gap. In addition, theheight of the pressing amount limiting members 30 is not limited to aparticular value as long as the pressing amount limiting members 30 canlimit the amount of pressing the paper 3 caused by the pressing members102.

Next, the pressing amount limiting member 30 disposed below the pressingmember 102 is described with reference to FIGS. 9( b), and 12 through16. FIG. 12 is another explanatory view showing that additional pressingamount limiting members 30 are disposed below the respective pressingmembers 102. FIG. 13 is a plan view of the print receiving member 27 inwhich the additional pressing amount limiting members 30 are disposedbelow the respective pressing members 102. Additionally, FIG. 14 shows asituation where the paper 3 is wider and the paper edge thereof extendsbeyond the pressing member 101. The amount of pressing the paper 3caused by the pressing members 102 can be adjusted by adjusting theelevation of the pressing amount limiting members 30 so disposed.

Although FIGS. 12 through 14 each shows an additional pressing amountlimiting member 30 disposed below the pressing member 101, such apressing amount limiting member 30 is not always necessary as shown inFIGS. 15 and 16. Even in these cases, the side portion of the paper 3can be pressed downward by the pressing member 101, and the paper 3 canbe kept flat in relation to the recording head 14 (FIG. 1) since theamount of pressing the paper 3 caused by the pressing members 102 can belimited by the pressing amount limiting members 30 below the pressingmembers 102.

Then, the pressing amount limiting member 30 disposed inside (or on theright-hand side of) the pressing member 102 is described with referenceto FIGS. 17 through 20 as well as FIG. 9( c). FIG. 17 is an explanatoryview showing that each of the additional pressing amount limitingmembers 30 is disposed inside the corresponding one of the pressingmembers 102. FIG. 17 is a plan view of the print receiving member 27 inwhich each of the additional pressing amount limiting members 30 isdisposed inside the corresponding one of the pressing members 102. Itshould be understood from FIGS. 17 and 18 that a rib 29, a thirdpressing member 102, and a pressing amount limiting member 30 aredisposed in this order in a direction from the side edge to the centerof the paper 3. The amount of pressing the paper 3 caused by thepressing members 102 can be adjusted by adjusting the elevation of thepressing amount limiting members 30 so disposed.

Although FIGS. 17 and 18 show a pressing amount limiting member 30disposed between the pressing member 101 and the outermost rib 29, sucha pressing amount limiting member 30 is not always necessary as shown inFIGS. 19 and 20. In these cases, the pressing member 101 can press theside portion of the paper 3 downward. Besides, the amount of pressingthe paper 3 caused by the pressing members 102 can be limited by thepressing amount limiting members 30 disposed inside the pressing members102, so that the paper 3 is kept flat in relation to the recording head14.

Referring to FIGS. 21( a) and 21(b), it is next described how thepressing members 101, 102 and the pressing amount limiting member 30 mayfunction differently depending on the size of the paper 3.

FIG. 21( a) is an explanatory view showing how the pressing amountlimiting member 30 functions to limit the amount of pressing the paper 3caused by the pressing member 102 when a sheet of paper 3 larger thanthe paper which the pressing member 102 is supposed to press downward isconveyed therein. In this case, the side portion of the larger paper 3is pressed downward by not the pressing member 102 but the pressingmember 101 in order to prevent the side portion from rising; and theprint area of the larger paper 3 is kept flat in relation to therecording head 14 (FIG. 1) by the pressing member 102 and the pressingamount limiting member 30 that limits the amount of pressing on thelarger paper 3 caused by the pressing member 102, thereby providing abetter quality image thereon.

On the other hand, when a sheet of paper 3 that is narrower than thepaper 3 illustrated in FIG. 21( a) is conveyed to the print receivingmember 27 (FIG. 11) as shown in FIG. 21( b), the narrower paper 3 can bepressed downward by the pressing member 102. In this case, a relativelylarge area of the side portion of the paper 3 may be pressed downward bythe pressing member 102, since no image is printed on the side portion.

In addition, it can be contemplated as other embodiments according tothe present invention that plural pressing amount limiting members X aredisposed outside the corresponding pressing members 102 and pluralpressing amount limiting members Y below the corresponding pressingmembers 101, 102.

The pressing amount limiting members X function to limit the amount ofpressing the paper 3 caused by the associated pressing members 102 whenthe edge of the paper 3 reaches the pressing member 101 (see FIG. 22(a)). Thus, the paper 3 can be kept flat in relation to the recordinghead 14 (FIG. 1) in an area in which the pressing amount limiting memberX limits the pressing amount, for better print quality. In addition tothe pressing amount limiting members X, the pressing amount limitingmembers Y can demonstrate a pressing amount limiting effect by adjustingthe elevation thereof. Therefore, the paper 3 can be kept flat inrelation to the recording head 14 (FIG. 1).

On the other hand, when a narrower paper whose edge does not reach thepressing member 101 is conveyed therein, the pressing amount limitingmember Y disposed below the associated pressing member 102 that pressesthe side portion of the paper 3 downward can limit the amount ofpressing the paper 3 caused by the pressing member 102. In addition,adjusting the elevation of the pressing amount limiting members (i.e.,30, X, Y) can reduce or increase the limiting amount caused by thepressing members 102.

As stated above, according to this embodiment in which the pluralpressing amount limiting members 30, X, Y are provided, the pressingamount limiting effect can be appropriately exhibited depending on userneeds.

By the way, the present invention is not limited to the embodimentsspecifically disclosed herein, but various alterations and modificationsmay be applied without departing from the scope of the invention setforth in accompanying claims.

The present application is based on Japanese Patent Applications No.2006-146861, filed on May 26, 2006, and No. 2007-065640, filed on Mar.14, 2007 with the Japanese Patent Office, the entire contents of whichare hereby incorporated by reference.

1-24. (canceled)
 25. A paper conveying apparatus comprising: multiplepaper pressing members configured to include at least one paper pressingmember which presses a side of a sheet of paper in a directionorthogonal to a paper conveying direction, and other paper pressingmembers which press a portion of the sheet of paper other than the side,wherein a pressing mount of the at least one paper pressing member isgreater than the pressing amounts of the other paper pressing members ina perpendicular direction with respect to a surface of the sheet ofpaper.
 26. The paper conveying apparatus as claimed in claim 25, whereinthe other paper pressing member are arranged at location to press a sideof a sheet of paper having a small width when the sheet of paper havingthe small width is conveyed.
 27. The paper conveying apparatus asclaimed in claim 25, further comprising one or more support membersconfigured to support the sheet of paper from below.
 28. The paperconveying apparatus as claimed in claim 25, further comprising at leastone pressing amount limiting member configured to press the side of thesheet of paper and to limit the pressing amounts of the multiple paperpressing members.
 29. The paper conveying apparatus as claimed in claim28, wherein the at least one pressing amount limiting member, whichpressed the side of the sheet of paper, supports the sheet of paper frombelow.
 30. The paper conveying apparatus as claimed in claim 28, whereinthe at least one pressing amount limiting member, which presses the sideof the sheet of papers, is arranged in a vicinity of at least one of themultiple paper pressing members.
 31. The paper conveying apparatus asclaimed in claim 30, wherein the vicinity is within a range in which thesheet of paper is supported and pressed up by the multiple paperpressing members for pressing the side of the sheet of paper.
 32. Thepaper conveying apparatus as claimed in claim 28, wherein the at leastone pressing amount limiting member limits the pressing amount byadjusting height thereof.
 33. The paper conveying apparatus as claimedin claim 28, wherein the at least one pressing amount limiting member isarranged outside the side of the sheet of paper in the directionorthogonal at the paper conveying direction in which the multiple paperpressing members press the sheet of paper,
 34. The paper conveyingapparatus as claimed in claim 28, wherein the at least one pressingamount limiting member is arranged outside the multiple paper pressingmember, which the press of the sheet of paper, in the directionorthogonal to the paper conveying direction.
 35. The paper conveyingapparatus as claimed in claim 28, wherein the at least one pressingamount limiting member includes a first pressing amount limiting partwhich is arranged outside the multiple paper pressing member, whichpress the side of the sheet of paper, in the direction orthogonal to thepaper conveying direction; and a second pressing amount limiting partwhich is arranged below.
 36. The paper conveying apparatus as claimed inclaim 25, further including: a print receiving member disposed opposinga print head that prints on the sheet of paper; a conveyor rollerconfigured to convey the sheet of paper to the print receiving member;and a pressing roller configured to press the sheet of paper on theconveyor roller, wherein the multiple paper pressing members press thesheet of paper on the print receiving member.
 37. The paper conveyingapparatus as claimed in claim 36, further including one or moresupporting member disposed on the print receiving member.
 38. An imageforming apparatus comprising at least the paper conveying apparatus ofclaim 25.